Case



Dec. 22, 1953 HILL ET AL 2,663,491

CASE

Filed Jan. 16. 1950 3 Sheets-Sheet l 3n nentors //'//)2y 697/ arm BB 6320676 A. /I////?/ attorney 1953 l. HILL ET AL 63,491

CASE

Filed Jan. 16. 1950 4 3 Sheets-Sheet 2 v 3nnentors Gttornegs I. HILL ET AL Dec. 22, 1953 CASE 5 Sheets-Sheet 5 Filed Jan. 16, 1950 4.1!!1'1 IIIIIIIII .IJIIIIIIIIIIII ling/11147111111 IIIIIIIIIIIII'III'IIIIIIIIIIIII I 4" YIIIIIII 6? 3maentors and M/k/ (Ittorneg s #14229 7/// ugfaf L.

Patented Dec. 22, 1953 CASE Irving Hill and George L. Miller, Lawrence, Kans., assignors to The Lawrence Paper Company, Lawrence, Kans., a corporation of Kansas Application January 16, 1950, Serial No. 138,770

3 Claims.

This invention relates to cases formed of corrugated, solid fiber or similar stifi board and has for its principal object to provide a case of this character with top and bottom fiaps having interlocks that are formed as parts of the flaps and which are easily manipulated and which securely retain the flaps in closed position.

Other objects of the invention are to provide flap interlocks for such cases wherein the interlocks are entirely within the boundaries of the flaps so that no additional material is required in constructing the case; to provide interlocks having no protruding parts that make uneven bearing surfaces for the case; to provide interlocks that do not require supplemental fastening means such as tape or stitching; to provide flap interlocks which have their interlocking efiioiency enhanced by the contents to be placed in the case; and to provide interlocks that are readily released when opening up the cases and for collapsing the cases when the cases are to be stored or shipped for reuse.

Further objects of the invention are to provide an interlock for the fiaps of a stifi board case including a specially scored corner on one flap adapted for insertion through bias slotlike openings in the underlying flap and to provide a skid element for guiding the corner into locking position.

In accomplishing these and other objects of the invention hereinafter pointed out, We have provided improved structure, the preferred forms of which are illustrated in the accompanying drawings wherein:

Fig. 1 is a perspective view of a case having top and bottom fiaps equipped with interlocks embodying features of the present invention.

Fig. 2 is a perspective view of the case showing the top flaps in open position and parts of the case broken away to better illustrate the interlocks of the bottom flaps. V

Fig. 3 is an enlarged fragmentary perspective view of one end of the case particularly illustrating the position of the flaps prior to engagement of the interlocks.

Fig. 4 is a similar view showing the interlocks moving into position to lock the flaps together.

Fig. 5 is a plane view of the blank from which the case is formed.

Fig. 6 is a section on the line 6--6 of Fig. 4 illustrating entrance of one of the corner locks into the slot of an underlying flap, the corner lock being shown as guided into position by means of a skid tab.

Fig. 7 is a similar section after the flaps are in interlocked position.

Fig. 8 is an enlarged perspective view similar to Figs. 3 and 4 but showing the flaps in inter locked relation.

Fig. 9 is a section on the line 9-9 of Fig. 8 to illustrate the tongue and slot engagement of the interlocking portions of the flaps. V

Fig. 10 shows a modification of the invention wherein the corner tabs fold back instead of being pushed forward.

Referring more in detail to the drawings:

I designates a case formed of corrugated solid fiber or similar stiff board material and having top and bottom flaps equipped with interlocking features in accordance with the present invention whereby the case is adapted for shipping eggs and other merchandise involving reuse of the case and opening for inspection.

The case is formed of a substantially rectangular sheet 2 having longitudinally spaced scores 3 and 4 inset inwardly of the longitudinal side edges 5 and 6 of the sheet and transverse scores I, 8 and 9 registering with slits II), II, I2, I3, I4 and I5 that extend inwardly from the outer edges to the scores 3 and 4. The end adjacent the score 9 has a projecting portion I6 that is offset outwardly intermediate the scores 3 and 4 and which is provided with a transverse score I! that registers with the end edges I8 and I9 which continue outwardly from the scores 3 and 4. The scores thus define substantially elongated rectangular areas 20 and 2| and relatively shorter areas 22 and 23 which constitute respectively the sides 2425 and ends 26-41 of the case illustrated in Fig. 1 when the blank is folded on the scores I, 8. 9 and H to bring the extension I6 into engagement with the corresponding portion at the opposite end of the blank as later described. The portions of the blank on the outer side of the score 4 and intermediate the slits therein constitute --longitudinal bottom flaps 28 and 29 and end bottom flaps 30 and 3| while the portions at the opposite side constitute top longitudinal flaps 32 and 33 and top end flaps 34 and 35. The ends 22 and 23 may be provided below the score 3 with handhold openings 36.

The structure of the blank thus far described is conventional and conforms to the construction of that for the usual case. The bottom and top closure flaps, however, are formed to have interlocks as now to be described.

The bottom closure flaps may overlap each other in various arrangements. For example, the longitudinal bottom fiapsmay overlap the end flaps as shown, the end flaps may overlap the longitudinal flaps, or the 'end flaps overlap one 3 of the longitudinal bottom flaps and underlie the other longitudinal bottom flap. The top closure flaps may be similarly arranged, however, the drawings show the end flaps as being adapted to overlie the longitudinal flaps. In any event, the corner of each overlying flap is provided with corner tabs adapted to engage bias-arranged slots in the underlying flap to form interlocks by which the flaps are secured together when in closed relation. 7

For example, the bottom flaps 28 and 29 have the corners thereof traversed by spaced scores 37 and 38 that converge slightly;'from the outerg edges 6 toward the end edges forming one side of the slits l3, l4, l and the end edge 19 to provide triangularly shaped tabs 39 which are adapted to be offset from the plane of the longie portions 44 of sufiicient width to pass freely the v 7 thickness of the corner tabs when the corner tabs are passed therethrough as later described. The ends 45 and 46 of the slots, however, are relatively narrower than the thickness of the corner tabs so that the ends of the slots bind the ends of the offsets intermediate the scores 37 and 38 as indicated at 4! and 48 when these portions of the corner tabs are pushed through the slots.

In order to resist retractive movement of the tabs in the slots, tongues 49 may be provided intermediate the ends of the slots which are adapted to engage in slots 50 that are provided in corresponding relation within the offsets 49. Since the locking slots for both longitudinal'flaps are located in the end flaps, one of the slots, for example, the slot 43 is of shorter length so as to leave ample amount of material therebetween and prevent unnecessary weakening of the material intermediate the slots. If desired, the top or bottom edges of the slot may be crushed or made thinner to facilitate entrance of the corner tabs as later described. While the drawing shows the slots and scores for the interlocks as being arranged at about 90, it is obvious that the angles may be changed either way to facilitate the lock on various sizes and shapes of cases. I

In the illustrated form of top closure, the top end flaps are provided with the angularly arranged spaced scores 5| and 52 to provide lock tabs 53 and 54 and the underlying ends of the longitudinal flaps 32 and 33 are provided with the angularly arranged slots 55 and 56 corresponding with the interlocking tabs and slots v previously described in connection with the bottom flaps. The scores 5| and 52 extend from the outer edges 5 of the flaps and converge toward the end edges of the end flaps. The slots 55 and 55 are arranged in corresponding relation on the underlying longitudinal flaps andhave are inserted through the slots and the ends of the oifsets 6i engage in the restricted ends 57 and 58 of the slots, the tongues 55 will slip into the openings 60. y

In order to facilitate entrance of the corner flaps when the case has been packed, the longitudinal side flaps have tongues 92 that are formed in the corners of the flaps by substantially U- shaped slits 63, the terminals of the slits terminating short of the slots to provide ample mate rial to prevent breaking through of the material. These tongues are subsequently folded retractively to underlie the slots and provide skids which direct the corner flaps as later described.

The blank thus described is folded on the score 8 to bring the side edge 64 of the portion 22 into registry with the score I! and into engagement with the flange portion. It so that it may be secured by a series of metal staples or stitching as indicated at 65 to thereby connect the'end wall with the adjacent side wall. The blank may then be formed into a rectangular enclosure by bending on the other score lines- 7 and 9. The endmost bottom flaps 30 and EH are then folded inwardly and the longitudinal flaps 28 and 29 are folded thereover with the locking tabs positioned so that the points thereof enter the wide portions of the slots 42 and 43. The tabs 38 bend on the scores 37 and 38 and slide under the inner faces of the end flaps until the scores 37 register with the slots. At this point the end portions of the offsets 40 enter the restricted ends 45 and 46 of the slots and the tabs are moved to their full position under the end flaps with the inner face of the longitudinal flaps in contact with the outer face of the end flaps. When moving into this position the tongues 49 spring through the openings 5i) and further enhance interlocking engagement between the flaps. This completes assembly of the bottom and the case may be turned rightside up for insertion of a liner 66- which may be formed of a single strip of the board-like material bent intermediate its ends on a score 61 to provide a mid rib 68 of double thickness extending from the top of the case to'the bottom where the board is bent outwardly on scores 69 and Hi to provide bottoms II and 72 extending over the exposed portions of the locking tabs as shown in Fig. 2. The ends of the board are then bent on the scores 13 to provide end portions 74 engaging the inner faces of the ends of the case as shown in Fig. 3. The end portions M are provided with openings 15 registering with thehandhold-openings 36 in the ends of the case and the portions 15 forming the openings 75 are moved outwardly through the handholds to overlap the outer faces of the ends of the case and form smooth rounding edges for the upper portions of the handholds and to retain the ends of the liner against the ends of the case.

In order to support the mid rib in vertical position, the sides of the case may be provided with inwardly extending tongues 71 engaging between the plies of the mid rib as shown in Fig. 2.

The merchandise, for example, eggs, is packed within the compartments 18 and 19 formed on the respective sides of the mid rib up to substantially the level of the upper edges of the case walls. 'It is obvious that by reason of the shape of the lock tabs and the stiif character of the board from which the case is constructed that the Weight of the contents acting upon the bottoms of the compartments clamp the locking tabs to prevent the locking tabs from sliding out of the slots. Consequently, the bottom flaps cannot open up as long as the contents are in the case.

After insertion of the contents, the longitudinal side flaps 32 and 33 are turned inwardly over the top of the case and the end flaps 34 and 35 are folded thereover so that the corners of the lock tabs 53 and 54 pass through the wider portions of the slots 55 and 56 as shown in Fig. 4 to engage the skid tabs 62 which are then resting upon the contents of the case. The skid tabs 62 thus provide easy entrance of the corner lock tabs 53 and 55 and guide them into position as they are pushed through the slot-like openings 55 and 56 until the offset portions pass into gripping contact with the restricted ends of the slots 57 and 58. At this point the tongues 59 slip through the openings 66 in the lock tab and retain the ofiset portions of the lock tabs in the slots with the corner tabs extending under the side flaps.

The case is readily opened for inspection of the contents at any time by applying pressure under the end flaps 34 and 35 to effect withdrawal of the lock tabs 53 and 54 during which movement the retaining tongues 58 slide out of the openings 60 and permit release of the flaps. After inspection the closure flaps are returned to closed position and are secured by the interlocks as previously described.

After the contents have been removed from the case, the case is readily collapsed by withdrawing the liner and disengaging the interlocks of the top and bottom flaps, after which the sides are hinged on the scores 8 and I! to flatten the case to permit stacking thereof with other cases for storage or shipment for reuse.

In Fig. is illustrated a modified form of the invention in which the skid tab 62 is located relatively to the slot 56 so that the locking tab 53 may be turned retractively instead of being pushed forwardly as in the first described form of the invention.

While we have particularly described the invention in connection with a box or container having closures formed by both top and bottom flaps, it is obvious that the invention may be carried out in securing the bottom flaps of a removable lid type box as well as various portions of other types of stiff box structures.

It is also obvious that the tuck flap and skid tab of the present invention may be adapted to boxes or cartons having closures of various forms and that the position of the skid tab and lock flap may be arranged sideways or cornerways to accommodate them to the particular box structure.

What we claim and desire to secure by Letters Patent is:

1. In a stiff boar-d case having overlapping flaps, one of said flaps having a bias arranged slot and provided with a tongue projecting into said slot, and the other flap having spaced scores extending diagonally across the corner of said other flap to provide a corner tab offset from the plane of said flap to facilitate passage through said slot and movement of said corner into contact with the underside of said flap having the slot and said offset portion into position contained in said slot, said offset portion having an opening for receiving said tongue.

2. In a stiff board case having overlapping flaps, one of said flaps having a bias arranged slot and provided with a tongue projecting into said slot, a skid tab formed from said flap and bent retractively across said slot on the side opposite the other of said fiaps, and spaced scores extending diagonally across the corner of said other flap to provide a corner tab offset from the plane of said flap to facilitate movement of said corner into contact with the skid tab for guiding the corner tab into contact with the underside of said flap having the slot and said offset portion into a position contained in said slot, said offset portion having an opening into which said tongue engages when the oifset portion is in said slot.

3. In a stiff board case having overlapping flaps, one of said flaps having a slot-like opening and the other having a locking tab adapted to be projected through said opening and having an offset adapted to engage in said slot, said offset having an opening, and a projection extending into the slot-like opening for receiving sai tongue.

IRVING HILL. GEORGE L. MILLER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,670,647 Alter May 22, 1928 2,102,048 Walstrom Dec. 14, 1937 2,334,114 Maston, Jr. Nov. 9, 1943 2,355,578 Williams Aug. 8, 1944 2,361,603 Cohen et al Oct. 31, 1944 2,393,356 Fallert Jan. 22, 1946 2,448,428 Lambert June 15, 1948 

